Rev 4509 | Go to most recent revision | Show entire file | Ignore whitespace | Details | Blame | Last modification | View Log | RSS feed
Rev 4509 | Rev 4552 | ||
---|---|---|---|
Line 40... | Line 40... | ||
40 | #include <errno.h> |
40 | #include <errno.h> |
41 | #include <string.h> |
41 | #include <string.h> |
42 | #include <adt/hash_table.h> |
42 | #include <adt/hash_table.h> |
43 | #include <adt/list.h> |
43 | #include <adt/list.h> |
44 | #include <assert.h> |
44 | #include <assert.h> |
45 | #include <futex.h> |
45 | #include <fibril_sync.h> |
46 | 46 | ||
47 | /** Each instance of this type describes one interval of freed VFS indices. */ |
47 | /** Each instance of this type describes one interval of freed VFS indices. */ |
48 | typedef struct { |
48 | typedef struct { |
49 | link_t link; |
49 | link_t link; |
50 | fs_index_t first; |
50 | fs_index_t first; |
Line 66... | Line 66... | ||
66 | 66 | ||
67 | /** Sorted list of intervals of freed indices. */ |
67 | /** Sorted list of intervals of freed indices. */ |
68 | link_t freed_head; |
68 | link_t freed_head; |
69 | } unused_t; |
69 | } unused_t; |
70 | 70 | ||
71 | /** Futex protecting the list of unused structures. */ |
71 | /** Mutex protecting the list of unused structures. */ |
72 | static futex_t unused_futex = FUTEX_INITIALIZER; |
72 | static FIBRIL_MUTEX_INITIALIZE(unused_lock); |
73 | 73 | ||
74 | /** List of unused structures. */ |
74 | /** List of unused structures. */ |
75 | static LIST_INITIALIZE(unused_head); |
75 | static LIST_INITIALIZE(unused_head); |
76 | 76 | ||
77 | static void unused_initialize(unused_t *u, dev_handle_t dev_handle) |
77 | static void unused_initialize(unused_t *u, dev_handle_t dev_handle) |
Line 87... | Line 87... | ||
87 | { |
87 | { |
88 | unused_t *u; |
88 | unused_t *u; |
89 | link_t *l; |
89 | link_t *l; |
90 | 90 | ||
91 | if (lock) |
91 | if (lock) |
92 | futex_down(&unused_futex); |
92 | fibril_mutex_lock(&unused_lock); |
93 | for (l = unused_head.next; l != &unused_head; l = l->next) { |
93 | for (l = unused_head.next; l != &unused_head; l = l->next) { |
94 | u = list_get_instance(l, unused_t, link); |
94 | u = list_get_instance(l, unused_t, link); |
95 | if (u->dev_handle == dev_handle) |
95 | if (u->dev_handle == dev_handle) |
96 | return u; |
96 | return u; |
97 | } |
97 | } |
98 | if (lock) |
98 | if (lock) |
99 | futex_up(&unused_futex); |
99 | fibril_mutex_unlock(&unused_lock); |
100 | return NULL; |
100 | return NULL; |
101 | } |
101 | } |
102 | 102 | ||
103 | /** Futex protecting the up_hash and ui_hash. */ |
103 | /** Mutex protecting the up_hash and ui_hash. */ |
104 | static futex_t used_futex = FUTEX_INITIALIZER; |
104 | static FIBRIL_MUTEX_INITIALIZE(used_lock); |
105 | 105 | ||
106 | /** |
106 | /** |
107 | * Global hash table of all used fat_idx_t structures. |
107 | * Global hash table of all used fat_idx_t structures. |
108 | * The index structures are hashed by the dev_handle, parent node's first |
108 | * The index structures are hashed by the dev_handle, parent node's first |
109 | * cluster and index within the parent directory. |
109 | * cluster and index within the parent directory. |
Line 229... | Line 229... | ||
229 | * There are no freed indices, allocate one directly |
229 | * There are no freed indices, allocate one directly |
230 | * from the counter. |
230 | * from the counter. |
231 | */ |
231 | */ |
232 | *index = u->next++; |
232 | *index = u->next++; |
233 | --u->remaining; |
233 | --u->remaining; |
234 | futex_up(&unused_futex); |
234 | fibril_mutex_unlock(&unused_lock); |
235 | return true; |
235 | return true; |
236 | } |
236 | } |
237 | } else { |
237 | } else { |
238 | /* There are some freed indices which we can reuse. */ |
238 | /* There are some freed indices which we can reuse. */ |
239 | freed_t *f = list_get_instance(u->freed_head.next, freed_t, |
239 | freed_t *f = list_get_instance(u->freed_head.next, freed_t, |
Line 242... | Line 242... | ||
242 | if (f->first++ == f->last) { |
242 | if (f->first++ == f->last) { |
243 | /* Destroy the interval. */ |
243 | /* Destroy the interval. */ |
244 | list_remove(&f->link); |
244 | list_remove(&f->link); |
245 | free(f); |
245 | free(f); |
246 | } |
246 | } |
247 | futex_up(&unused_futex); |
247 | fibril_mutex_unlock(&unused_lock); |
248 | return true; |
248 | return true; |
249 | } |
249 | } |
250 | /* |
250 | /* |
251 | * We ran out of indices, which is extremely unlikely with FAT16, but |
251 | * We ran out of indices, which is extremely unlikely with FAT16, but |
252 | * theoretically still possible (e.g. too many open unlinked nodes or |
252 | * theoretically still possible (e.g. too many open unlinked nodes or |
253 | * too many zero-sized nodes). |
253 | * too many zero-sized nodes). |
254 | */ |
254 | */ |
255 | futex_up(&unused_futex); |
255 | fibril_mutex_unlock(&unused_lock); |
256 | return false; |
256 | return false; |
257 | } |
257 | } |
258 | 258 | ||
259 | /** If possible, coalesce two intervals of freed indices. */ |
259 | /** If possible, coalesce two intervals of freed indices. */ |
260 | static void try_coalesce_intervals(link_t *l, link_t *r, link_t *cur) |
260 | static void try_coalesce_intervals(link_t *l, link_t *r, link_t *cur) |
Line 300... | Line 300... | ||
300 | if (f->first == index + 1) { |
300 | if (f->first == index + 1) { |
301 | f->first--; |
301 | f->first--; |
302 | if (lnk->prev != &u->freed_head) |
302 | if (lnk->prev != &u->freed_head) |
303 | try_coalesce_intervals(lnk->prev, lnk, |
303 | try_coalesce_intervals(lnk->prev, lnk, |
304 | lnk); |
304 | lnk); |
305 | futex_up(&unused_futex); |
305 | fibril_mutex_unlock(&unused_lock); |
306 | return; |
306 | return; |
307 | } |
307 | } |
308 | if (f->last == index - 1) { |
308 | if (f->last == index - 1) { |
309 | f->last++; |
309 | f->last++; |
310 | if (lnk->next != &u->freed_head) |
310 | if (lnk->next != &u->freed_head) |
311 | try_coalesce_intervals(lnk, lnk->next, |
311 | try_coalesce_intervals(lnk, lnk->next, |
312 | lnk); |
312 | lnk); |
313 | futex_up(&unused_futex); |
313 | fibril_mutex_unlock(&unused_lock); |
314 | return; |
314 | return; |
315 | } |
315 | } |
316 | if (index > f->first) { |
316 | if (index > f->first) { |
317 | n = malloc(sizeof(freed_t)); |
317 | n = malloc(sizeof(freed_t)); |
318 | /* TODO: sleep until allocation succeeds */ |
318 | /* TODO: sleep until allocation succeeds */ |
319 | assert(n); |
319 | assert(n); |
320 | link_initialize(&n->link); |
320 | link_initialize(&n->link); |
321 | n->first = index; |
321 | n->first = index; |
322 | n->last = index; |
322 | n->last = index; |
323 | list_insert_before(&n->link, lnk); |
323 | list_insert_before(&n->link, lnk); |
324 | futex_up(&unused_futex); |
324 | fibril_mutex_unlock(&unused_lock); |
325 | return; |
325 | return; |
326 | } |
326 | } |
327 | 327 | ||
328 | } |
328 | } |
329 | /* The index will form the last interval. */ |
329 | /* The index will form the last interval. */ |
Line 333... | Line 333... | ||
333 | link_initialize(&n->link); |
333 | link_initialize(&n->link); |
334 | n->first = index; |
334 | n->first = index; |
335 | n->last = index; |
335 | n->last = index; |
336 | list_append(&n->link, &u->freed_head); |
336 | list_append(&n->link, &u->freed_head); |
337 | } |
337 | } |
338 | futex_up(&unused_futex); |
338 | fibril_mutex_unlock(&unused_lock); |
339 | } |
339 | } |
340 | 340 | ||
341 | static fat_idx_t *fat_idx_create(dev_handle_t dev_handle) |
341 | static fat_idx_t *fat_idx_create(dev_handle_t dev_handle) |
342 | { |
342 | { |
343 | fat_idx_t *fidx; |
343 | fat_idx_t *fidx; |
Line 350... | Line 350... | ||
350 | return NULL; |
350 | return NULL; |
351 | } |
351 | } |
352 | 352 | ||
353 | link_initialize(&fidx->uph_link); |
353 | link_initialize(&fidx->uph_link); |
354 | link_initialize(&fidx->uih_link); |
354 | link_initialize(&fidx->uih_link); |
355 | futex_initialize(&fidx->lock, 1); |
355 | fibril_mutex_initialize(&fidx->lock); |
356 | fidx->dev_handle = dev_handle; |
356 | fidx->dev_handle = dev_handle; |
357 | fidx->pfc = FAT_CLST_RES0; /* no parent yet */ |
357 | fidx->pfc = FAT_CLST_RES0; /* no parent yet */ |
358 | fidx->pdi = 0; |
358 | fidx->pdi = 0; |
359 | fidx->nodep = NULL; |
359 | fidx->nodep = NULL; |
360 | 360 | ||
Line 363... | Line 363... | ||
363 | 363 | ||
364 | fat_idx_t *fat_idx_get_new(dev_handle_t dev_handle) |
364 | fat_idx_t *fat_idx_get_new(dev_handle_t dev_handle) |
365 | { |
365 | { |
366 | fat_idx_t *fidx; |
366 | fat_idx_t *fidx; |
367 | 367 | ||
368 | futex_down(&used_futex); |
368 | fibril_mutex_lock(&used_lock); |
369 | fidx = fat_idx_create(dev_handle); |
369 | fidx = fat_idx_create(dev_handle); |
370 | if (!fidx) { |
370 | if (!fidx) { |
371 | futex_up(&used_futex); |
371 | fibril_mutex_unlock(&used_lock); |
372 | return NULL; |
372 | return NULL; |
373 | } |
373 | } |
374 | 374 | ||
375 | unsigned long ikey[] = { |
375 | unsigned long ikey[] = { |
376 | [UIH_DH_KEY] = dev_handle, |
376 | [UIH_DH_KEY] = dev_handle, |
377 | [UIH_INDEX_KEY] = fidx->index, |
377 | [UIH_INDEX_KEY] = fidx->index, |
378 | }; |
378 | }; |
379 | 379 | ||
380 | hash_table_insert(&ui_hash, ikey, &fidx->uih_link); |
380 | hash_table_insert(&ui_hash, ikey, &fidx->uih_link); |
381 | futex_down(&fidx->lock); |
381 | fibril_mutex_lock(&fidx->lock); |
382 | futex_up(&used_futex); |
382 | fibril_mutex_unlock(&used_lock); |
383 | 383 | ||
384 | return fidx; |
384 | return fidx; |
385 | } |
385 | } |
386 | 386 | ||
387 | fat_idx_t * |
387 | fat_idx_t * |
Line 393... | Line 393... | ||
393 | [UPH_DH_KEY] = dev_handle, |
393 | [UPH_DH_KEY] = dev_handle, |
394 | [UPH_PFC_KEY] = pfc, |
394 | [UPH_PFC_KEY] = pfc, |
395 | [UPH_PDI_KEY] = pdi, |
395 | [UPH_PDI_KEY] = pdi, |
396 | }; |
396 | }; |
397 | 397 | ||
398 | futex_down(&used_futex); |
398 | fibril_mutex_lock(&used_lock); |
399 | l = hash_table_find(&up_hash, pkey); |
399 | l = hash_table_find(&up_hash, pkey); |
400 | if (l) { |
400 | if (l) { |
401 | fidx = hash_table_get_instance(l, fat_idx_t, uph_link); |
401 | fidx = hash_table_get_instance(l, fat_idx_t, uph_link); |
402 | } else { |
402 | } else { |
403 | fidx = fat_idx_create(dev_handle); |
403 | fidx = fat_idx_create(dev_handle); |
404 | if (!fidx) { |
404 | if (!fidx) { |
405 | futex_up(&used_futex); |
405 | fibril_mutex_unlock(&used_lock); |
406 | return NULL; |
406 | return NULL; |
407 | } |
407 | } |
408 | 408 | ||
409 | unsigned long ikey[] = { |
409 | unsigned long ikey[] = { |
410 | [UIH_DH_KEY] = dev_handle, |
410 | [UIH_DH_KEY] = dev_handle, |
Line 415... | Line 415... | ||
415 | fidx->pdi = pdi; |
415 | fidx->pdi = pdi; |
416 | 416 | ||
417 | hash_table_insert(&up_hash, pkey, &fidx->uph_link); |
417 | hash_table_insert(&up_hash, pkey, &fidx->uph_link); |
418 | hash_table_insert(&ui_hash, ikey, &fidx->uih_link); |
418 | hash_table_insert(&ui_hash, ikey, &fidx->uih_link); |
419 | } |
419 | } |
420 | futex_down(&fidx->lock); |
420 | fibril_mutex_lock(&fidx->lock); |
421 | futex_up(&used_futex); |
421 | fibril_mutex_unlock(&used_lock); |
422 | 422 | ||
423 | return fidx; |
423 | return fidx; |
424 | } |
424 | } |
425 | 425 | ||
426 | void fat_idx_hashin(fat_idx_t *idx) |
426 | void fat_idx_hashin(fat_idx_t *idx) |
Line 429... | Line 429... | ||
429 | [UPH_DH_KEY] = idx->dev_handle, |
429 | [UPH_DH_KEY] = idx->dev_handle, |
430 | [UPH_PFC_KEY] = idx->pfc, |
430 | [UPH_PFC_KEY] = idx->pfc, |
431 | [UPH_PDI_KEY] = idx->pdi, |
431 | [UPH_PDI_KEY] = idx->pdi, |
432 | }; |
432 | }; |
433 | 433 | ||
434 | futex_down(&used_futex); |
434 | fibril_mutex_lock(&used_lock); |
435 | hash_table_insert(&up_hash, pkey, &idx->uph_link); |
435 | hash_table_insert(&up_hash, pkey, &idx->uph_link); |
436 | futex_up(&used_futex); |
436 | fibril_mutex_unlock(&used_lock); |
437 | } |
437 | } |
438 | 438 | ||
439 | void fat_idx_hashout(fat_idx_t *idx) |
439 | void fat_idx_hashout(fat_idx_t *idx) |
440 | { |
440 | { |
441 | unsigned long pkey[] = { |
441 | unsigned long pkey[] = { |
442 | [UPH_DH_KEY] = idx->dev_handle, |
442 | [UPH_DH_KEY] = idx->dev_handle, |
443 | [UPH_PFC_KEY] = idx->pfc, |
443 | [UPH_PFC_KEY] = idx->pfc, |
444 | [UPH_PDI_KEY] = idx->pdi, |
444 | [UPH_PDI_KEY] = idx->pdi, |
445 | }; |
445 | }; |
446 | 446 | ||
447 | futex_down(&used_futex); |
447 | fibril_mutex_lock(&used_lock); |
448 | hash_table_remove(&up_hash, pkey, 3); |
448 | hash_table_remove(&up_hash, pkey, 3); |
449 | futex_up(&used_futex); |
449 | fibril_mutex_unlock(&used_lock); |
450 | } |
450 | } |
451 | 451 | ||
452 | fat_idx_t * |
452 | fat_idx_t * |
453 | fat_idx_get_by_index(dev_handle_t dev_handle, fs_index_t index) |
453 | fat_idx_get_by_index(dev_handle_t dev_handle, fs_index_t index) |
454 | { |
454 | { |
Line 457... | Line 457... | ||
457 | unsigned long ikey[] = { |
457 | unsigned long ikey[] = { |
458 | [UIH_DH_KEY] = dev_handle, |
458 | [UIH_DH_KEY] = dev_handle, |
459 | [UIH_INDEX_KEY] = index, |
459 | [UIH_INDEX_KEY] = index, |
460 | }; |
460 | }; |
461 | 461 | ||
462 | futex_down(&used_futex); |
462 | fibril_mutex_lock(&used_lock); |
463 | l = hash_table_find(&ui_hash, ikey); |
463 | l = hash_table_find(&ui_hash, ikey); |
464 | if (l) { |
464 | if (l) { |
465 | fidx = hash_table_get_instance(l, fat_idx_t, uih_link); |
465 | fidx = hash_table_get_instance(l, fat_idx_t, uih_link); |
466 | futex_down(&fidx->lock); |
466 | futex_down(&fidx->lock); |
467 | } |
467 | } |
468 | futex_up(&used_futex); |
468 | fibril_mutex_unlock(&used_lock); |
469 | 469 | ||
470 | return fidx; |
470 | return fidx; |
471 | } |
471 | } |
472 | 472 | ||
473 | /** Destroy the index structure. |
473 | /** Destroy the index structure. |
Line 481... | Line 481... | ||
481 | [UIH_INDEX_KEY] = idx->index, |
481 | [UIH_INDEX_KEY] = idx->index, |
482 | }; |
482 | }; |
483 | 483 | ||
484 | assert(idx->pfc == FAT_CLST_RES0); |
484 | assert(idx->pfc == FAT_CLST_RES0); |
485 | 485 | ||
486 | futex_down(&used_futex); |
486 | fibril_mutex_lock(&used_lock); |
487 | /* |
487 | /* |
488 | * Since we can only free unlinked nodes, the index structure is not |
488 | * Since we can only free unlinked nodes, the index structure is not |
489 | * present in the position hash (uph). We therefore hash it out from |
489 | * present in the position hash (uph). We therefore hash it out from |
490 | * the index hash only. |
490 | * the index hash only. |
491 | */ |
491 | */ |
492 | hash_table_remove(&ui_hash, ikey, 2); |
492 | hash_table_remove(&ui_hash, ikey, 2); |
493 | futex_up(&used_futex); |
493 | fibril_mutex_unlock(&used_lock); |
494 | /* Release the VFS index. */ |
494 | /* Release the VFS index. */ |
495 | fat_index_free(idx->dev_handle, idx->index); |
495 | fat_index_free(idx->dev_handle, idx->index); |
496 | /* Deallocate the structure. */ |
496 | /* Deallocate the structure. */ |
497 | free(idx); |
497 | free(idx); |
498 | } |
498 | } |
Line 522... | Line 522... | ||
522 | 522 | ||
523 | u = (unused_t *) malloc(sizeof(unused_t)); |
523 | u = (unused_t *) malloc(sizeof(unused_t)); |
524 | if (!u) |
524 | if (!u) |
525 | return ENOMEM; |
525 | return ENOMEM; |
526 | unused_initialize(u, dev_handle); |
526 | unused_initialize(u, dev_handle); |
527 | futex_down(&unused_futex); |
527 | fibril_mutex_lock(&unused_lock); |
528 | if (!unused_find(dev_handle, false)) |
528 | if (!unused_find(dev_handle, false)) |
529 | list_append(&u->link, &unused_head); |
529 | list_append(&u->link, &unused_head); |
530 | else |
530 | else |
531 | rc = EEXIST; |
531 | rc = EEXIST; |
532 | futex_up(&unused_futex); |
532 | fibril_mutex_unlock(&unused_lock); |
533 | return rc; |
533 | return rc; |
534 | } |
534 | } |
535 | 535 | ||
536 | void fat_idx_fini_by_dev_handle(dev_handle_t dev_handle) |
536 | void fat_idx_fini_by_dev_handle(dev_handle_t dev_handle) |
537 | { |
537 | { |
538 | unused_t *u; |
538 | unused_t *u; |
539 | 539 | ||
540 | u = unused_find(dev_handle, true); |
540 | u = unused_find(dev_handle, true); |
541 | assert(u); |
541 | assert(u); |
542 | list_remove(&u->link); |
542 | list_remove(&u->link); |
543 | futex_up(&unused_futex); |
543 | fibril_mutex_unlock(&unused_lock); |
544 | 544 | ||
545 | while (!list_empty(&u->freed_head)) { |
545 | while (!list_empty(&u->freed_head)) { |
546 | freed_t *f; |
546 | freed_t *f; |
547 | f = list_get_instance(u->freed_head.next, freed_t, link); |
547 | f = list_get_instance(u->freed_head.next, freed_t, link); |
548 | list_remove(&f->link); |
548 | list_remove(&f->link); |